Kevin Phillips, in "Reagan's Decline Is Good News for the GOP" {Outlook, Aug. 2}, announces the end of the conservative era and forecasts a resurgence of "progressivism" and radicalism. Time will tell whether Mr. Phillips is right, but no reader can arrive at these conclusions based on the scanty evidence presented in the article.

For instance, Mr. Phillips triumphantly noted that "some 50 to 60 percent of Americans believe that the 1988 elections should move the United States in a new direction." Now, I would be willing to wager that polls show this before any election. The marvel is that the percentage is as low as 50 to 60 percent. Polls between the 1930s and the 1970s consistently showed voters eager for a change; this did not mean, however, that the liberal ethos enshrined by Franklin Roosevelt was displaced by something else. Similarly, as long as liberal Democrats cannot offer an attractive alternative to Reagan administration conservatism, the president's agenda could very well outlast his terms in office.

Mr. Phillips could disprove my point by citing proof that people increasingly want their taxes raised, want to expand government spending, do not believe able-bodied welfare recipients should work, object to values being taught in school and are now aficionados of the combined agenda of the left-wing interest groups that still dominate the Democratic Party. Unfortunately, if he has such evidence, he has concealed it from his readers.

Mr. Phillips' analysis just doesn't wash. Ronald Reagan is the man who made possible modern American conservatism. He continues to enjoy strong support from the American people. His conservative ideas dominate the debate, with no sign of being superseded any time soon.

Maybe rampant radicalism is just around the corner -- if so, Kevin Phillips should invest in tie-dye shirts and mantra beads. But he should pardon reasonable people for being skeptical about his prophecies.

GARY L. BAUER

Assistant to the President for Policy Development

The White House

Washington